From 00292bbf769620dea923dbd906afd88955f7ea19 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Fri, 23 Mar 2012 13:47:52 -0400 Subject: [PATCH] mtdchar: kill persistently held vfsmount ... and mtdchar_notifier along with it; just have ->drop_inode() that will unconditionally get evict them instead of dances on mtd device removal and use simple_pin_fs() instead of kern_mount() Signed-off-by: Al Viro --- drivers/mtd/mtdchar.c | 53 +++++++++++++------------------------------ 1 file changed, 16 insertions(+), 37 deletions(-) diff --git a/drivers/mtd/mtdchar.c b/drivers/mtd/mtdchar.c index c57ae92ebda4..28c585ffc8af 100644 --- a/drivers/mtd/mtdchar.c +++ b/drivers/mtd/mtdchar.c @@ -39,7 +39,6 @@ #include static DEFINE_MUTEX(mtd_mutex); -static struct vfsmount *mtd_inode_mnt __read_mostly; /* * Data structure to hold the pointer to the mtd device as well @@ -75,7 +74,9 @@ static loff_t mtdchar_lseek(struct file *file, loff_t offset, int orig) return -EINVAL; } - +static int count; +static struct vfsmount *mnt; +static struct file_system_type mtd_inodefs_type; static int mtdchar_open(struct inode *inode, struct file *file) { @@ -92,6 +93,10 @@ static int mtdchar_open(struct inode *inode, struct file *file) if ((file->f_mode & FMODE_WRITE) && (minor & 1)) return -EACCES; + ret = simple_pin_fs(&mtd_inodefs_type, &mnt, &count); + if (ret) + return ret; + mutex_lock(&mtd_mutex); mtd = get_mtd_device(NULL, devnum); @@ -106,7 +111,7 @@ static int mtdchar_open(struct inode *inode, struct file *file) goto out; } - mtd_ino = iget_locked(mtd_inode_mnt->mnt_sb, devnum); + mtd_ino = iget_locked(mnt->mnt_sb, devnum); if (!mtd_ino) { put_mtd_device(mtd); ret = -ENOMEM; @@ -141,6 +146,7 @@ static int mtdchar_open(struct inode *inode, struct file *file) out: mutex_unlock(&mtd_mutex); + simple_release_fs(&mnt, &count); return ret; } /* mtdchar_open */ @@ -162,6 +168,7 @@ static int mtdchar_close(struct inode *inode, struct file *file) put_mtd_device(mtd); file->private_data = NULL; kfree(mfi); + simple_release_fs(&mnt, &count); return 0; } /* mtdchar_close */ @@ -1175,10 +1182,15 @@ static const struct file_operations mtd_fops = { #endif }; +static const struct super_operations mtd_ops = { + .drop_inode = generic_delete_inode, + .statfs = simple_statfs, +}; + static struct dentry *mtd_inodefs_mount(struct file_system_type *fs_type, int flags, const char *dev_name, void *data) { - return mount_pseudo(fs_type, "mtd_inode:", NULL, NULL, MTD_INODE_FS_MAGIC); + return mount_pseudo(fs_type, "mtd_inode:", &mtd_ops, NULL, MTD_INODE_FS_MAGIC); } static struct file_system_type mtd_inodefs_type = { @@ -1187,26 +1199,6 @@ static struct file_system_type mtd_inodefs_type = { .kill_sb = kill_anon_super, }; -static void mtdchar_notify_add(struct mtd_info *mtd) -{ -} - -static void mtdchar_notify_remove(struct mtd_info *mtd) -{ - struct inode *mtd_ino = ilookup(mtd_inode_mnt->mnt_sb, mtd->index); - - if (mtd_ino) { - /* Destroy the inode if it exists */ - clear_nlink(mtd_ino); - iput(mtd_ino); - } -} - -static struct mtd_notifier mtdchar_notifier = { - .add = mtdchar_notify_add, - .remove = mtdchar_notify_remove, -}; - static int __init init_mtdchar(void) { int ret; @@ -1224,19 +1216,8 @@ static int __init init_mtdchar(void) pr_notice("Can't register mtd_inodefs filesystem: %d\n", ret); goto err_unregister_chdev; } - - mtd_inode_mnt = kern_mount(&mtd_inodefs_type); - if (IS_ERR(mtd_inode_mnt)) { - ret = PTR_ERR(mtd_inode_mnt); - pr_notice("Error mounting mtd_inodefs filesystem: %d\n", ret); - goto err_unregister_filesystem; - } - register_mtd_user(&mtdchar_notifier); - return ret; -err_unregister_filesystem: - unregister_filesystem(&mtd_inodefs_type); err_unregister_chdev: __unregister_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS, "mtd"); return ret; @@ -1244,8 +1225,6 @@ static int __init init_mtdchar(void) static void __exit cleanup_mtdchar(void) { - unregister_mtd_user(&mtdchar_notifier); - kern_unmount(mtd_inode_mnt); unregister_filesystem(&mtd_inodefs_type); __unregister_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS, "mtd"); }